[GTOJOE228]

On a non power brake 70 Judge what color is the master?

Thanks,

Joe

[SWEETJUDGE]

cast iron

[motorcitymusclecar]

The master cylinder was painted black on all the cars. The MC casting was painted black then got machined and assembled. So the body was black and all the machined surfaces were bare metal. This is pictured in the accesory guide for each year car - in the 69 it shows a picture of power brakes and it is clear the mc is black and so are the calipers and many other cast iron parts that had been machined

[SWEETJUDGE]

hmmmmmmmmmmmmmm

[taximan]

Mine is painted black, and have been told by multiple judges that either is correct. Was told by Sawruk that his feeling is that black is correct, but the supplier finished the raw steel and put a water based black coating that easily came off.


Similar to the emissions sticker controversy on 69's. The emmission sticker on top of the radiator support is correct. However, they were tissue paper water based stick ons, and most of them were gone by delivery.

[Dar]

FWIW this information is out of the 1970 Pontiac Factory Service manual, I can't speak for 1969, but they use the oval body (different all together). Also I'm not saying this is absolutely correct for all, just pointing out what I have found.

In the 1970 manual they show a few Master Cylinders. One for "Standard Brakes", another "Delco Maraine Power Brake", and a third "Bendix Power Brake". What is interesting is the manual states "The Bendix power brake unit can be identified by its all-black color and external piston stop screw on the master cylinder".

This Bendix M/C is easy to identify as you can easilly see the secondary pistion stop set screw in the middle of the the very bottom of the M/C. Personally I don't know if these were even used, or how commom they are on GTO's.

I have an early 70 GTO and a mid 70 GTO and both use the Delco Moraine Power Brake Units. They can be identified by having the secondary pistion stop screw located in the bottom of the front fluid reservoir. It mentions nothing about the color so I assume it doesn't have any, meaning natural cast iron. Also note that the Standard Brake M/C also has no mention of color in the service manual, and it looks very close to the Delco-Moraine Power Unit also with its secondary piston stop screw located in the front fluid resevoir.

So in a nut shell according to the Factory Service Manual only the bedix type M/C should be black. In any case I am restoring my Judge (with it's Delco-Maraine Unit) cast iron color. Also in speaking with the original owner whom I bought the car from, he didn't recall the M/C being black when he bought it new, and in fact thought it was unpainted cast.

[68alpinebluegto]

The 10A Pontiac Assembly 70 Judge Conv I painted had the original MC and it was Cast iron, errrr I mean surface rusted...

[henley]

FOR MY TWO CENTS WORTH I BELIEVE THEY WERE BLACK PHOSPHATE PLATED PRIOR TO MACHINING. I HAVE TWO NOS MASTER CYLINDERS, ONE DATED 69 AND THE OTHER DATED 70. BOTH ARE BLACK PHOSHATE PLATED. MINE IS CURRENTLY AT STEVE D'S IN CA GETTING REPLATED. HE DOES EXCELLANT REPLATING AND IT IS NOT VERY EXPENSIVE.

[68alpinebluegto]

Many times there were differences in finishes for parts destined for the assembly line vs parts destined for Over The Counter Sales... An assembly line worker could care less about some surface rust PLUS the parts were used quicker so rust is less of an issue. Black Phosphate would have lasted on the 70 Judge Conv. as it still has all the rest of the original phosphating under the hood. (45k miles and garage stored it's whole life)

[lockec]

I'll go with the cheap black paint theory. I have found traces of black paint on most of the ones I've seen. I have an NOS 70 EB with the cheap black paint treatment.

[Francois Raby]

My 1972 455 ho gto sat in a basement from 1976 to 2006 and was driven in 4winters only. Ckeck the black treatment on the master and the GX sticker. GX for what? thanks from montreal.

[Matador-IV]

Originally Posted by Francois Raby

My 1972 455 ho gto sat in a basement from 1976 to 2006 and was driven in 4winters only. Ckeck the black treatment on the master and the GX sticker. GX for what? thanks from montreal.Attachment 131591

I believe an original master cyl. would have bleeder screws.

[Francois Raby]

I'm not so sure about that. I've seen cars with or without them in books and elsewhere. More infos needed ? thanks

[SWEETJUDGE]

i think 69s were the only ones with bleeders..... all the ones ive seen have been rusty so im for cast iron.....

chucky how about a pic of your NOS masters?? have steved post Id love to see it. IS the EA stamped in the half moon from NOS or did that get stamped when installed???

[gloryrestoparts]

Originally Posted by SWEETJUDGE

i think 69s were the only ones with bleeders..... all the ones ive seen have been rusty so im for cast iron.....

no. I have 67, 68, 69 and 70 masters with bleeders. think I may have a 71 also. too much stuff

[motorcitymusclecar]

Bleeder masters were on all cars up into the mid to late 70's. The 67-69 had the round master with the bleeders and the 70-77 had the square with the bleeders. From my experience all the disc brake masters had bleeders until around 76-77

[henley]

Here are some pictures!

[Uncle Judge]

Originally Posted by SWEETJUDGE

i think 69s were the only ones with bleeders..... all the ones ive seen have been rusty so im for cast iron.....

chucky how about a pic of your NOS masters?? have steved post Id love to see it. IS the EA stamped in the half moon from NOS or did that get stamped when installed???

The factory original 1970 (EB) coded units as well as the 1971-72 (BE) coded units ALL used bleeders. And yes, they were also black. I can supply pics of NOS units (like Chuckies above) as well as low mile originals.